On Thu, Nov 20, 2014 at 4:21 AM, Jeff Davis <pg...@j-davis.com> wrote: >> The >> bad news, to borrow a phrase from Peter Geoghegan, is that it's an >> unprincipled deadlock; a user confronted with the news that her >> parallel scan has self-deadlocked will be justifiably dismayed. > > You seem to be raising this as a show-stopping problem, and I'm not > convinced that it is.
Well, what I'm saying is that at very minimum we have to be able detect deadlocks, and we have two plausible designs for avoiding that: 1. Modify the deadlock detector to know about lock groups. 2. Propagate pre-existing locks from the user backend to all the workers. I initially proposed #1, but now I think #2 solves more of the problems for less code. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers